Pipe coupling



FIG. 1 is an isometric view of our design for a pipe coupling;

FIG. 2 is a top view of the design for the pipe coupling shown in FIG. 1;

FIG. 3 is a bottom view of the design for the pipe coupling shown in FIG. 1;

FIG. 4 is a left side view of the design for the pipe coupling shown in FIG. 1, the right side view being a mirror image thereof;

FIG. 5 is a front view of the design for the pipe coupling shown in FIG. 1; and,

FIG. 6 is a rear view of the design for the pipe coupling shown in FIG. 1.

The broken lines shown in the figures illustrate portions of the pipe coupling that farm no part of the claimed design. 

CLAIM We claim the ornamental design for a pipe coupling, as shown and described. 